Cam device for controlling the needles or knitting accessories of circular knitting-machine

ABSTRACT

A control cam in the cam-box of a circular knitting machine comprises a support disk with a prismatic cam body pivotally mounted and axially movable in a space defined between counter cams for the passage of needle butts. The prismatic body has two active cam faces of unequal length located on opposite sides of the pivoting axis. The cam body is spring urged towards an operative position, notches in the support disk defining three selectable angular positions of the cam body in which the active faces cooperate with the counter cams to provide tracks for guiding the needle butts to knitting, looping or tucking, and non-knitting positions respectively.

United States Patent [1 1 Bourgeois 111 3,795,119 [45'] Mar. '5, 1974 [75] Inventor:

[73] Assignee: Etudes Et Bonneterie S.A

- Lausanne, Switzerland [22] Filed: Nov. 12, 1971 [21] Appl. No.: 198,132

Norbert Bourgeois, Troyes, France [30] Foreign Application Priority Data Nov. 26, 1971 Switzerland 17522/71 [52] US. Cl....., 66/20, 66/57 [51] Int. Cl D04b 15/32 [58] Field of Search... 66/57, 40, 50, 50 A, 25, 78, 66/50 R, 20

[56] References Cited UNITED STATES PATENTS 3,405,542 10/1968 Beckenstein .Q.. 66/57 FOREIGN PATENTS OR APPLICATIONS 306,687 2/1928 Great Britain 66/78 527,645 7/1956 Canada 66/57 Primary Examiner-W; C. Reynolds Assistant ExaminerA. M. Falik E Attorney, Agent, or FirmWenderoth, Lind & Ponack [5 7] ABSTRACT A Control cam in the Cam-box of a Circular knitting machine comprises a support disk with a prismatic cam body pivotally mounted and axially movable in a space defined between Counter cams for the passage of needle butts. The prismatic body has two active cam faces of unequal length located On opposite sides of the pivoting axis. The Cam body is spring urged towards an operative position, notches in the support disk defining three selectable angular positions of the Cam body in which the active faces cooperate with the Counter Cams to provide tracks for guiding theneedle butts to knitting, looping or tucking, and non-knitting positions respectively.

7 Claims, 8 Drawing Figures PATENTED 51974 3,795.1 l9

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NORBERT BOURGEOIS, Inventor Attorneys PATENTEDHAR 519M 3,795,119

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' NORBERT BOURGEOIS Inventor Attorneys A CAM DEVICE FOR CONTROLLING THE NEEDLES OR KNITTING ACCESSORIES OF CIRCULAR KNITTING-MACHINE This invention relates to devices for controlling the needles or knitting accessories of circular knitting machines.

In circular knitting machines, it is known to use raising cams comprising slidably or pivotally mounted cams on conventional cam-boxes and adapted to act on the control butts of the needles so that the latter can occupy one of three basic positions, namely: a knitting position, in which the needles are placed in a condition such that their respective hooks can seize the feeding yarn and such that new stitches are formed; a tucking or looping position, in which the hooks can seize the yarn which is added to the preceedingly formed stitches without the formation of new stitches; and a non knitting position, in which the needle hooks cannot seize the yarn and conserve the preceedingly formed stitches.

It has, for example, been proposed to use tandem cams to provide these different positions of the needles. While offering a certain facility of manoeuvre because of their autonomy, these tandem cams have a relatively large bulk, hardly compatible with the space available in present-day multisystems machines.

It has also been proposed to use mobile cams with a single slope whose top can occupy three different levels corresponding to the three positions for the needles. In this case, it is difficult to ensure the correct positioning of the needle hooks and latches in relation to the yarn guide; To remedy these drawbacks tests have been carried out with a fixed cam upstream ofa mobile knitting cam, a counter cam being associated with this latter mobile cam to form a guide track for the needle butts. This solution, which is suitable for machines with two opposite needle beds with alternating needles, is not suitable when the needles are disposed face to face.

According to the invention, which aims to remedy these drawbacks, there is provided a device for controlling the needles or knitting accessories of a circular knitting machine, comprising a cam-box having at least two counter cams providing therebetween a space for the passage of needle butts, and a cam pivotally mounted about and axially movable along an axis passing through said space, said cam having a prismatic body with at least two cam faces spaced apart from and extending on either side of said axis, said cam being axially movable between an inoperative axially retracted position in which the cam is clear of said space for the passage of needle butts and an operative position in which said carn faces lie in said space, and means for defining three angular positions of the cam in the operative position, in which three angular positions said cam faces cooperate with the counter cams to respectively provide three tracks for guiding needle butts into positions corresponding to knitting, looping and non knitting.

The accompanying drawings show, schematically and by way of example, two embodiments of the invention. In the drawings:

FIGS. 1 to 3 are perspective views of a first embodiment of device.

FIG. 4 is a perspective view of a detail of the device shown in FIGS. 1 to 3.

FIG. 5 is a cross section taken along line x-x' of FIG.

1, with the device secured to part of a knitting machine.

FIGS. 6 and 7 are respectively seen plan views of two devices according to a second embodiment; and

FIG. 8 is an outline cross section of a part of a circular knitting machine comprising the devices of FIGS. 6 and 7, taken along lines y-y' and z-z' of these Figures respectively.

The device of FIGS. 1, 2, 3 and 5 comprises a cambox section 1 for a circular knitting machine with two rotary needle beds and is intended to control the horizontal needles of the needle bearing plate. The section 1 is secured to a stationary ring 2 by means of a screw 3 (FIG. 5) and is laterally held by means of two pins, not shown.

Counter-cams 5 and 6 are fixed on section 1 by means of screws 4; and a cam 7 is mounted radially in a sliding relationship to allow adjusting the desired size of the knitted stitches, this cam assembly leaving a free space within which can move the butts 8 of needles 9 which are slidingly mounted in the radial grooves of the needlebearing plate, not shown.

The three basic positions of the needles are obtained by means of a single pivotal cam 10 pivotally mounted about an axis 13 and having a prismatic body, two lateral faces 11 and 12 of which are tangential to and located on opposite sides of a circle 14 centred about the axis 13. These two faces 11 and 12 are adapted, according to the angular location of the cam 10, to act on the rear face 15 of the control butts 8 to bring the corresponding needles 9 from a non-knitting position into a knitting position and a tucking or looping position respectively. The face 11 is moreover adapted, for another angular location of the cam 10, to guide and hold the control butts 8 into a position corresponding to non-knitting of the needles, by acting in the manner of a counter cam on the surface 16 of the butts 8.

FIGS. 1 to 3 respectively illustrate the three different positions of the cam 10 corresponding to the three basic positions of the needles 9. Hence, in FIG. 1, the needle butts 8 which arrive in the non-knitting track 17 follow the track 18 formed by the face 11 of the cam 10 and the counter cam 5. After the knitted stitches have passed over the end of the latches, the books of the respective needles seize the fed yarn so that new stitches are formed. In FIG. 2, in the second position of the cam 10, the butts 8 follow the track 19 and these butts are only brought to the level of the end face 20 of the prismatic body. The hooks of the respective needles, the stitches of which have not passed by the end of the latches, seize the fed yarn without, the formation of new stitches.

Because of the particular disposition of the two faces 11 and 12 of the cam 10 in relation to the pivoting axis 13, the butts 8 follow needle tracks of strictly identical inclination, which enables easy and precise positioning of the conventional yarn guide, while avoiding the risks of damaging the needle latches and making knitting faults.

It is to be noted on FIG. 2 that the distance A between the axis 13 and the face 1 1 is substantially equal to the distance B between a perpendicular line through the axis 13 and the edge 21 of the counter cam 5, in other words the distance between the axis 13 and the front face 16 of the butts 8 when the latter pass through the non-knitting track 17. This disposition enables, as shown in FIG. 3 where the cam 10 is in its third angular position, use of the face 1 l to radially guide and maintain the butts 8 by acting on their front faces 16 in a manner to extend the track 17.

Naturally, the particular disposition of the two faces 1 l and 12 of the cam enables the possibility of using either one of these two faces to radially guide and maintain the butts 8.

The cam 10 shown in detail in FIG. 4 comprises a support member in the form of a disk 22 provided with a concentric socket 23 and the periphery of which disk has three radial notches 24, 25 and 26 adapted tocooperate with a cylindrical locking pin 27 (FIGS. 1 and 5). These notches correspond respectively to the three angular positions knitting, tucking and non-knitting in which the cam 10 can be locked.

Referring to the cross section of FIG. 5, the section I has a housing 28 in which the support disk 22 of cam 10 can be axially manoeuvred and the depth of which is sufficient to enable the support disk to be moved out of contact with the locking pin 27 and consequently to be pivoted. The section 1 additionally comprises a bore 29 forming a bearing for the socket 23 and a compression spring 30 surrounding this socket. This spring is supported between the bottom of a housing 31 and the support disk 22 in a manner to urge the cam towards its operative position in engagement with the locking pin 27 and in which the base or outer face of the support disk 22 comes into abutment with an inner bearing face of the counter cams 5 and 6.

An elbow-shaped notch 32 is provided in the socket 23 thus enabling the introduction of a maneuvering tool for axially moving the cam 10 against the action of the spring 30 so as to angularly free the cam and allow selection of the angular position thereof.

In the embodiment of FIGS. 6 to 8, a cam-carrying section 34 for the control of horizontal needles (FIG. 6) and a cam-carrying section 35 for the control of vertical needles (FIG. 7) of a circular knitting machine each comprise two cam spaces or paths for providing tracks for the passage of the needle butts. These sections 34 and 35 are fixed on stationary rings 36, 37 respectively by means of screws 38, 39 (FIG. 8) and are laterally held by means of pins, not shown.

Referring to FIG. 6, counter cams 41, 42, 43 forming between themselves the two said cam paths are fixed on the section 34 by means of screws 40. Two schematically shown types of needles, 45 and 48, are provided, each slidably mounted in radial grooves of the needle carrier 49, FIG. 8. The needles 45 comprise a singlecontrol and knocking over butt 44 and the needles 48 each comprise a knocking over butt 46 and a control butt 47.

On the section 34 is also arranged a conventional radially slidable cam for adjustment of the desired dimensions of the knitted stitches, this cam 50 being common to the two types of needles and acting on the bases of the butts 44, 46.

The three basic positions are obtained for each of the two types of needles respectively by means of pivotal earns 10', 10" similar to the cam 10 ofthe previous embodiment. The butts 44 of the needles 45 pass into the non-knitting track 17 and follow the track 18' in a manner to bring the needles 45 into the knitting position, while the upper butts 47 of the needles 48 pass into the non-knitting track 17" and follow the track 19' to bring these needles into the looping position.

As is more clearly illustrated on FIG. 8, and contrary to the preceeding embodiment, the faces of the cams l0, 10 are arranged to act solely on the upper part of the corresponding control butts and, in the operative position, are housed in the thickness of the counter cams. As shown in FIG. 6, each cam l0, 10" comprises a counter cam 51, 51' made together with a support disk 22, 22" respectively and forming with the face 20, 20" of the cam 10, 10" a guide track 52, 52 for the respective control butts when the needles are brought into the intermediate looping position.

The height 53, 53' (FIG. 8) of the operative parts of the earns 10, 10" engaged in the region of the control butts is slightly less than the height of the locked support disk 22', 22". This feature enables the operator who has to modify the angular position of the cams 10, 10" to unlock, against the action of compression springs 30', 30", all of the cams of the machine and to pivot them into the chosen position. The support disks once more lock under the action of the springs 30, 30 before the cams 10', 10" can influence the needles. These cams can then, during a rotation of the machine and still under the action of the springs 30', 30", engage one by one in the region of the needle butts, either with a zone of the butts whose height differs from the normal height, or with a narrow zone without needles.

The cam bearing section 35 for the vertical needles also comprises three counter earns 54, 55, 56 fixed by screws 40 and a slidable cam 57 common to the two types of needle and whose position can be adjusted according to the desired dimensions of the knitted stitches; this cam is moreover laterally movable to make the needles adopt the two conventional positions corresponding to delayed or synchronized timing.

On FIG. 7, the cam 10 is shown oriented so that its face 12' forms a track 58 adapted to guide the needles with an upper control butt 59 into the knitting position, while the cam 10 is oriented to form, by its active face 12", a track 60 adapted to hold the needle butts 61 in a position corresponding to non knitting.

The described device can be manufactured in an economical manner, it is oflow bulk, and enables positioning of the needles in their three basic positions by a simple manoeuvre.

I claim:

1. A device for controlling the needles or knitting accessories of a circular knitting machine, comprising a cam-box having at least two counter cams providing therebetween a space for the passage of needle butts, and a cam pivotally mounted about and axially movable along an axis passing through said space, said cam having a prismatic body with at least two cam faces spaced apart from and extending on either side of said axis, said cam being axially movable between an axially retracted position to effect a change in its angular position and an operative position in which said cam faces lie in said space, and means for defining three angular positions of the cam in the operative position, in which three angular positions said cam faces cooperate with the counter cams to respectively provide three tracks for guiding needle butts into positions corresponding to knitting, tucking and non-knitting.

2. A device according to claim 1, in which said prismatic body of the pivotally mounted cam is integral with a support member having recesses corresponding to said three angular positions, means for cooperating with one of said recesses when the cam is in the operative position to lock said cam in a selected one of the three angular positions, a spring axially urging the cam from the retracted position towards the operative position, and means for facilitating axial movement of the cam from the operative to the retracted position against the action of said spring so as to angularly free the cam.

3. A device according to claim 1, in which the cambox comprises three counter cams forming therebetween two spaces for the passage of needle butts, each space being provided with a cam pivotally mounted about and axially slidable along an axis passing through the space.

4. A device according to claim 1, in which said pivotally mounted cam comprises a further counter cam forming a part of a guide track for the needle butts when the cam is in one of said three angular positions.

5. A device according to claim 1, in which the face of said prismatic body adapted to define with the counter earns the track corresponding to non-knitting is one of two faces extending on opposite sides of said axis.

6. A device according to claim 1, in which said prismatic body comprises a substantially pointed end, an end face, and first and second active side faces converging from the end face to the pointed end, said first and second faces being symmetrically angularly and positionally disposed on opposite sides of said axis, said end face making acute and oblique angles with the first and second faces respectively.

7. A device according to claim 6, in which in a first angular position of the cam in the operative position said first face defines with a slope of a first counter cam a track corresponding to raising needle butts to a knitting position; in a second angular position of the cam in the operative position said second face defines with said slope of the first counter cam a track corresponding to raising needle butts to a tucking position; and in a third angular position of said cam in the operative position said first face defines with a surface of a second counter cam a track for guiding needle butts in a position corresponding to non-knitting. 

1. A device for controlling the needles or knitting accessories of a circular knitting machine, comprising a cam-box having at least two counter cams providing therebetween a space for the passage of needle butts, and a cam pivotally mounted about and axially movable along an axis passing through said space, said cam having a prismatic body with at least two cam faces spaced apart from and extending on either side of said axis, said cam being axially movable between an axially retracted position to effect a change in its angular position and an operative position in which said cam faces lie in said space, and means for defining three angular positions of the cam in the operative position, in which three angular positions said cam faces cooperate with the counter cams to respectively provide three tracks for guiding needle butts into positions corresponding to knitting, tucking and non-knitting.
 2. A device according to claim 1, in which said prismatic body of the pivotally mounted cam is integral with a support member having recesses corresponding to said three angular positions, means for cooperating with one of said recesses when the cam is in the operative position to lock said cam in a selected one of the three angular positions, a spring axially urging the cam from the retracted position towards the operative position, and means for facilitating axial movement of the cam from the operative to the retracted position against the action of said spring so as to angularly free the cam.
 3. A device according to claim 1, in which the cam-box comprises three counter cams forming therebetween two spaces for the passage of needle butts, each space being provided with a cam pivotally mounted about and axially slidable along an axis passing through the space.
 4. A device according to claim 1, in which said pivotally mounted cam comprises a further counter cam forming a part of a guide track for the needle butts when the cam is in one of said three angular positions.
 5. A device according to claim 1, in which the face of said prismatic body adapted to define with the counter cams the track corresponding to non-knitting is one of two faces extending on opposite sides of said axis.
 6. A device aCcording to claim 1, in which said prismatic body comprises a substantially pointed end, an end face, and first and second active side faces converging from the end face to the pointed end, said first and second faces being symmetrically angularly and positionally disposed on opposite sides of said axis, said end face making acute and oblique angles with the first and second faces respectively.
 7. A device according to claim 6, in which in a first angular position of the cam in the operative position said first face defines with a slope of a first counter cam a track corresponding to raising needle butts to a knitting position; in a second angular position of the cam in the operative position said second face defines with said slope of the first counter cam a track corresponding to raising needle butts to a tucking position; and in a third angular position of said cam in the operative position said first face defines with a surface of a second counter cam a track for guiding needle butts in a position corresponding to non-knitting. 